SL2023-739/NSL PMI sensors

We would like to draw your attention to the use of PMI sensors for measuring cylinder pressure on MAN B&W two-stroke engines.
The cylinder pressure is used for various applications, such as balancing of maximum pressure, compression pressure, mean indicated pressure, fuel quality adjustment, and load estimation.

Moreover, it is utilised for the gas safety system on dual fuel engines. For all these applications, it is crucial to measure the cylinder pressure accurately and reliably during the lifetime of the PMI sensors.

Therefore, MAN Energy Solutions has approved two makers, namely ABB and Kistler, to produce sensors that fulfill the requirements for controlling the engine reliably and in compliance with our design.
It is important to note that the two makers use different techniques to measure the pressure. This means that the two PMI sensor makes cannot replace each other. Furthermore, these makes cannot be replaced by other makes.

Summary
This Service Letter underlines that the two currently approved makers of PMI sensors, ABB and Kistler, must not be interchanged or replaced with any other make.